>But does something like Evolution or LibreOffice really need to never assume that CHAR_BIT is not necessary 8, or that int might be less than 32, or that int64

>But does something like Evolution or LibreOffice really need to never assume that CHAR_BIT is not necessary 8, or that int might be less than 32, or that int64_t might not even be defined? No and why should they? I assume all these things routinely when I write code that I don't expect to run on "weird" systems. And I don't have to worry about int being less than 32 since I when I need this guarantee use "int32_t" like a civilized human being. The overhead is only here if you care to really write entirely portable C code but in practice very few people bother to do that outside of comp.lang.c. >It would be nice to have an ISO-standard superset of C that catalogs such assumptions. Basically, a "non-DSP, non-mainframe" version of C, that's portable across all modern non-exotic platforms, and provides definitions for as many things that are UB or implementation-defined in standard C as possible. POSIX C then? It assumes that chars are 8bits, that data and function pointers are castable and a bunch of other assumptions that are not possible in strict C. It also offers a richer API than C's stdlib. When I write C for a "non-DSP, non-mainframe" environment (that is, 99.9% of the time) I almost always target POSIX C, not strict ANSI.